Rotary grinding drum with panel-like lining elements



y 9, 1967 AKE w. WALLIN ETAL 3,318,537

ROTARY GRINDING DRUM WITH PANEL-LIKE LINTNG ELEMENTS Filed Nov. 19, 1964 1 2 Sheets-Sheet l 453 um M433 m4 final/(M y 1967 AKE w. WALLIN ETAL 3,318,537

ROTARY GRINDING DRUM WITH PANEL-LIKE TJINING ELEMENTS 2 Sheets-Sheet 2 Filed Nov. 19, 1964 United States Patent 3,318,537 ROTARY GRINDING DRUM WITH PANEL-LIKE LINING ELEMENTS Ake Wilhelm Wallin and Bo Klas Gerhard Persson, Tr elleborg, Sweden, assignors to Trelleborgs Gummi fabrrks Aktiebolag, Trelleborg, Sweden, a corporation of Sweden Filed Nov. 19, 1964, Ser. No. 412,416 Claims priority, application Sweden, Nov. 22, 1963, 12,901/ 63 2 Claims. (Cl. 241-183) ABSTRACT OF THE DISCLOSURE The invention aims at preventing or reducing the penetration of ground material into the gap between the lifting rib and the adjacent rubber panel, and it is important that the joint between two successive panels, when one panel overlaps the other with a lifting rib portion, cannot be widened because of the panel edge overlapped by the lifting rib portion leaving its correct position beneath the lifting rib portion under the action of the forces and deformation to which the panels are subjected during operation of the mill. This applies especially when the panel edge is clamped against the grinding chamber shell by the lifting rib portion since the clamping force, when the panel is of rubber, may create forces which tend to remove the panel edge from its correct position beneath the lifting rib portion.

This invention relates to an improved mill having a rotary grinding chamber with a cylindrical or substantially cylindrical boundary wall, a liner of axially directed and circumferentially successive rubber panels on the inner side of said boundary wall, and axially directed lifting ribs of rubber projecting into the grinding chamber from the inner side of said liner.

In prior-art mills of this type the lifting ribs have been formed as separate elements clamping the rubber panels in the boundary wall of the grinding chamber either in that the lifting ribs were wedged between the successive rubber panels or in that the lifting ribs were caused to clamp the facing edge portions of the rubber panels to the boundary wall of the grinding chamber. In practice, these two prior-art forms have proved unreliable in that the clamping is not particularly durable. This would seem to be due to the rubbing action and the impacts to which the lifting ribs are exposed in operation and which tend momentarily to open up a gap between the lifting rib and the adjoining rubber panel, into which gap ground pieces can penetrate, exerting a wearing and prying effect therein.

It has now been found possible to eliminate or in any case widely reduced the above drawback by the improvement in mills of the type indicated that an axially directed edge portion of each panel overlaps an adjoining edge portion of the next following panel and is designed so as to constitute one of the lifting ribs.

The above features of the invention and the advantages gained thereby will become apparent from the following description in which reference is made to the accompanying drawings illustrating a preferred embodiment of the invention. In the drawings:

FIG. 1 is a diagrammatic fragmentary cross-sectional view of the grinding chamber of a mill improved in accordance with the invention;

FIG. 2 is a fragmentary view, on a larger scale, of the mill grinding chamber shown in FIG. 1.

The grinding chamber of the mill illustrated in FIG. 1

3,318,537 Patented May 9, 1967 "ice ' However, the boundary wall of the grinding chamber could also be polygonal and thus only approximately cylindrical. Disposed on the inner side of the wall of the grinding chamber is a liner of axially directed and circumferentially successive rubber panels 2. Each rubber panel 2 substantially is of equal thickness throughout the main portion thereof. One axially directed edge portion of each panel 2, however, has a relatively thin flange 3 adjacent the wall '1 of the grinding chamber, said flange 3 projecting from the remaining panel 2 in the circumferential direction of the wall 1 and having at its outer end a nose 4 which is directed inwardly from said wall 1. The other axially directed edge portion of each panel 2 is formed as a lifting rib 5 integral with the panel and overlaps the adjoining edge portion of the next following panel. The edge portion of each panel 2 which is to form the lifting rib 5 thus has a surface 6 facing the grinding chamber wall 1, said surface 6 overlapping and bearing against the full thickness portion of the adjoining panel 2, and from the surface 6 there extends a projection 7 towards the grinding chamber wall 1 in order to engage the flange 3 and nose 4 of the adjoining panel 2 in the manner best seen from FIG. 2. Furthermore, within the region of the lifting rib 5 there is formed in each panel 2 an axially directed slot 8 for accommodating a fixation bar 9 which is adapted, by means of bolts 10 and nuts 11, to press those portions of two adjoining panels 2 which are situated between the bar 9 and the wall 1 against said wall 1 for clamping the liner to the boundary wall of the grinding chamber.

When the panels 2 having the lifting ribs 5 thereon are oriented in the manner appearing from the accompanying drawings in relation to the direction of rotation of the grinding chamber, which is marked by an arrow 12, it is obvious that the rubbing action and impacts exerted by the material to the ground and the grinding balls cannot open up any gap at the surface 6, through which ground pieces could penetrate in between two successive panels 2. Therefore, there cannot arise any such Wearing and prying effect in joint gaps of the liner as in the prior-art mills.

' What We claim and desire to secure by Letters Patent 1s:

1. A rotary grinding mill, comprising a substantially cylindrical rotary shell defining a grinding chamber, a liner on the inner surface of said shell, comprising a plurality of rubber panels, mounted in a close series around the inner circumference of said shell, a first and a second marginal portion on each of said panels, being oppositely located on each of said panels and extending axially of said shell, a lifting rib integrally formed on said first marginal portion of each of said panels and projecting into the grinding chamber, a flange integrally formed on said second marginal portion of each of said panels, said flange being thinner than the rest of said panel and extending along the inner surface of said shell, a nose integrally formed on the free axially extending edge of said flange, said nose projecting from said flange inwardly towards the center axis of said shell, and means on said first marginal portion of each of said panels engaging said flange of an adjacent one of said panels between said nose and the rest of said adjacent panel.

2. A rotary grinding mill, comprising a substantially cylindrical rotary shell defining a grinding chamber, a liner on the inner surface of said shell, comprising a plurality of rubber panels, mounted in a close series around the inner circumference of said shell, a first and a second marginal portion on each of said panels, being oppositely located on each of said panels and extending ing into the grinding chamber, a flange integrally formed on said second marginal portion of each of said panels,

said flange being thinner than the rest of said panel and 5 extending along the inner surface of said shell, a nose integrally formed on the free axially extending edge of said flange, said nose projecting from said flange inwardly towards the center axis of said shell, a projection on said first marginal portion of each of said panels, projecting 0 from said first marginal portion towards said shell and into engagement with said flange of an adjacent one of said panels between said nose and the rest of said adjacent panel, surface means on said first marginal portion of each of said panels and on said nose of an adjacent one of said panels, defining a slot extending axially of said shell, and

a fixation bar inserted insaid slot and fastened to said shell.

References Cited by the Examiner UNITED STATES PATENTS 7 1,132,909 3/l1915 Brinton 241' 1s3q 1,470,597 10/1923 Denny 241-183 X 1,538,620 5/1925 Canda 24 1183 1,601,956 10/1926 Gammeter 241-183 X 1,690,493 11/1928 Marcy 241183X V WILLIAM W. DYER, JR., Primary Examiner. 

1. A ROTARY GRINDING MILL, COMPRISING A SUBSTANTIALLY CYLINDRICAL ROTARY SHELL DEFINING A GRINDING CHAMBER, A LINER ON THE INNER SURFACE OF SAID SHELL, COMPRISING A PLURALITY OF RUBBER PANELS, MOUNTED IN A CLOSE SERIES AROUND THE INNER CIRCUMFERENCE OF SAID SHELL, A FIRST AND A SECOND MARGINAL PORTION ON EACH OF SAID PANELS, BEING OPPOSITELY LOCATED ON EACH OF SAID PANELS AND EXTENDING AXIALLY OF SAID SHELL, A LIFTING RIB INTEGRALLY FORMED ON SAID FIRST MARGINAL PORTION OF EACH OF SAID PANELS AND PROJECTING INTO THE GRINDING CHAMBER, A FLANGE INTEGRALLY FORMED ON SAID SECOND MARGINAL PORTION OF EACH OF SAID PANELS, SAID FLANGE BEING THINNER THAN THE REST OF SAID PANEL AND EXTENDING ALONG THE INNER SURFACE OF SAID SHELL, A NOSE INTEGRALLY FORMED ON THE FREE AXIALLY EXTENDING EDGE OF SAID FLANGE, SAID NOSE PROJECTING FROM SAID FLANGE INWARDLY TOWARDS THE CENTER AXIS OF SAID SHELL, AND MEANS ON SAID 